4. Arnebia guttata Bunge, Index Sem. Hort. Petrop. 7. 1840.
黄花软紫草 huang hua ruan zi cao
Arnebia thomsonii C. B. Clarke; A. tibetana Kurz; Lithospermum guttatum (Bunge) I. M. Johnston; Macrotomia guttata (Bunge) Farrer.
Herbs perennial or sometimes biennial. Roots containing purple dye. Stems usually 2-4, sometimes only 1, erect, much branched, 10-25 cm tall, densely spreading long hispid, short strigose. Leaves sessile, spatulate-linear to linear, 1.5-5.5 cm × 3-11 mm, densely hirsute, hairs discoid at base, apex obtuse. Inflorescences crowded; cymes 3-10 cm; bracts linear-lanceolate. Flowers heterostylous. Calyx lobes linear, 6-10 mm, to 1.5 cm in fruit, long hispid. Corolla yellow, tubular-campanulate, pubescent outside; limb 7-12 mm wide; lobes spreading, broadly ovate or semiorbicular, frequently purple spotted. Anthers oblong, ca. 1.8 mm. Style filiform, apex 2-lobed; stigma reniform. Nutlets light yellow-brown, triangular-ovate, 2.5-3 mm, tuberculate. Fl. and fr. Jun-Oct.
Gobi Desert, rocky slopes, gravelly marshes. W Gansu, N Hebei, Nei Mongol, Ningxia, Xinjiang, Xizang [Afghanistan, NW India, Kazakhstan, Kyrgyzstan, Mongolia, Pakistan, Russia, Tajikistan, Turkmenistan, Uzbekistan]
There are biennial and perennial groups within the species, the former predominantly in Russia and Mongolia, the latter in Xizang and Xinjiang (Arnebia tibetana). These groups, which lack the blackish purple spots on corolla lobes, probably represent distinct subspecies.
The roots are used medicinally.